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LinearGauge Class

LinearGauge Class

The LinearGauge displays a linear scale with an indicator that represents a single value and optional ranges to represent reference values.

If you set the gauge's LinearGauge.isReadOnly property to false, then users will be able to edit the value by clicking on the gauge.

Example

Heirarchy

Constructors

Properties

Methods

Events

Constructors

constructor

  • new LinearGauge(element: any, options?: any): LinearGauge

  • Initializes a new instance of the LinearGauge class.

    Parameters

    • element: any

      The DOM element that hosts the control, or a CSS selector for the host element (e.g. '#theCtrl').

    • Optional options: any

      JavaScript object containing initialization data for the control.

    Returns LinearGauge

Properties

direction

direction: GaugeDirection

Gets or sets the direction in which the gauge is filled.

The default value for this property is GaugeDirection.Right.

face

face: Range

Gets or sets the Range used to represent the gauge's overall geometry and appearance.

faceBounds

faceBounds: Rect

Gets the bounds of the gauge's face element.

This property is useful for positioning custom SVG elements on the gauge.

format

format: string

Gets or sets the format string used to display gauge values as text.

getText

getText: IGetGaugeText

Gets or sets a callback that returns customized strings used to display gauge values.

Use this property if you want to customize the strings shown on the gauge in cases where the format property is not enough.

If provided, the callback should be a function as that takes as parameters the gauge, the part name, the value, and the formatted value. The callback should return the string to be displayed on the gauge.

For example:

// callback to convert values into strings
gauge.getText = (gauge, part, value, text) => {
    switch (part) {
        case 'value':
            if (value <= 10) return 'Empty!';
            if (value <= 25) return 'Low...';
            if (value <= 95) return 'Good';
            return 'Full';
        case 'min':
            return 'EMPTY';
        case 'max':
           return 'FULL';
    }
    return text;
}

handleWheel

handleWheel: boolean

Gets or sets a value that determines whether the user can edit the gauge value using the mouse wheel.

The default value for this property is true.

hasShadow

hasShadow: boolean

Gets or sets a value that indicates whether the gauge displays a shadow effect.

The default value for this property is true.

hostElement

hostElement: HTMLElement

Gets the DOM element that is hosting the control.

isAnimated

isAnimated: boolean

Gets or sets a value that determines whether the Gauge should use animation to show value changes.

The default value for this property is true.

isDisabled

isDisabled: boolean

Gets or sets a value that determines whether the control is disabled.

Disabled controls cannot get mouse or keyboard events.

isReadOnly

isReadOnly: boolean

Gets or sets a value that indicates whether the user can edit the gauge value using the mouse and keyboard.

The default value for this property is true.

isTouching

isTouching: boolean

Gets a value that indicates whether the control is currently handling a touch event.

isUpdating

isUpdating: boolean

Gets a value that indicates whether the control is currently being updated.

max

max: number

Gets or sets the maximum value that can be displayed on the gauge.

For details about using the min and max properties, please see the Using the min and max properties topic.

min

min: number

Gets or sets the minimum value that can be displayed on the gauge.

For details about using the min and max properties, please see the Using the min and max properties topic.

origin

origin: number

Gets or sets the starting point used for painting the range.

By default, this property is set to null, which causes the value range to start at the gauge's minimum value, or zero if the minimum is less than zero.

pointer

pointer: Range

Gets or sets the Range used to represent the gauge's current value.

ranges

ranges: ObservableArray

Gets the collection of ranges in this gauge.

rightToLeft

rightToLeft: boolean

Gets a value indicating whether the control is hosted in an element with right-to-left layout.

showRanges

showRanges: boolean

Gets or sets a value that indicates whether the gauge displays the ranges contained in the ranges property.

If this property is set to false, the ranges contained in the ranges property are not displayed in the gauge. Instead, they are used to interpolate the color of the pointer range while animating value changes.

The default value for this property is true.

showText

showText: ShowText

Gets or sets the ShowText values to display as text in the gauge.

The default value for this property is ShowText.All for RadialGauge controls, and to ShowText.None for LinearGauge controls.

showTickText

showTickText: boolean

Gets or sets a property that determines whether the gauge should display the text value of each tick mark.

You can use CSS to style the tickmark text:

.wj-gauge .wj-tick-text text {
    opacity: 1;
    font-family: Courier;
    font-size: 8pt;
    fill: purple;
}

See also the showTicks and tickSpacing properties.

The default value for this property is false.

showTicks

showTicks: boolean

Gets or sets a property that determines whether the gauge should display tickmarks at each step (or tickSpacing) value.

The tickmarks can be formatted in CSS using the wj-gauge and wj-ticks class names. For example:

.wj-gauge .wj-ticks {
    stroke-width: 2px;
    stroke: white;
}

The default value for this property is **false.

stackRanges

stackRanges: boolean

Gets or sets a value that determines whether the ranges contained in the ranges collection should be stacked within the gauge.

By default, stackRanges is set to false, and the ranges in the ranges collection are displayed with the same thickness as the gauge's face.

Setting stackRanges to true causes the ranges to become narrower, and to be displayed side-by-side.

step

step: number

Gets or sets the amount to add to or subtract from the value property when the user presses the arrow keys or moves the mouse wheel.

tabOrder

tabOrder: number

Gets or sets a value of the tabindex attribute associated with the control.

tabindex attribute value can be defined statically for a Wijmo control by specifying it on the control's host HTML element. But this value can't be changed later during application lifecycle, because Wijmo controls have complex structure, and the control may need to propagate this attribute value to its internal element to work properly.

Because of this, to read or change control's tabindex dynamically, you should do it using this property.

thickness

thickness: number

Gets or sets the thickness of the gauge, on a scale between zero and one.

Setting the thickness to one causes the gauge to fill as much of the control area as possible. Smaller values create thinner gauges.

thumbSize

thumbSize: number

Gets or sets the size of the element that shows the gauge's current value, in pixels.

tickSpacing

tickSpacing: number

Gets or sets the spacing between tickmarks.

Set the showTicks property to true if you want the gauge to show tickmarks along its face. By default, the interval between tickmarks is defined by the step property.

Use the tickSpacing property to override the default and use a spacing that is different from the step value. Set the tickSpacing property to null to revert to the default behavior.

value

value: number

Gets or sets the value displayed on the gauge.

Static controlTemplate

controlTemplate: string

Gets or sets the template used to instantiate Gauge controls.

Methods

addEventListener

  • addEventListener(target: EventTarget, type: string, fn: any, capture?: boolean, passive?: boolean): void

  • Adds an event listener to an element owned by this Control.

    The control keeps a list of attached listeners and their handlers, making it easier to remove them when the control is disposed (see the dispose and removeEventListener methods).

    Failing to remove event listeners may cause memory leaks.

    The passive parameter is set to false by default, which means the event handler may call event.preventDefault(). If you are adding passive handlers to touch or wheel events, setting this parameter to true will improve application performance.

    For details on passive event listeners, please see Improving scrolling performance with passive listeners.

    Parameters

    • target: EventTarget

      Target element for the event.

    • type: string

      String that specifies the event.

    • fn: any

      Function to execute when the event occurs.

    • Optional capture: boolean

      Whether the listener should be handled by the control before it is handled by the target element.

    • Optional passive: boolean

      Indicates that the handler will never call preventDefault().

    Returns void

applyTemplate

  • applyTemplate(classNames: string, template: string, parts: Object, namePart?: string): HTMLElement

  • Applies the template to a new instance of a control, and returns the root element.

    This method should be called by constructors of templated controls. Therefore, this method is not available. It is responsible for binding the template parts to the corresponding control members.

    For example, the code below applies a template to an instance of an InputNumber control. The template must contain elements with the 'wj-part' attribute set to 'input', 'btn-inc', and 'btn-dec'. The control members '_tbx', '_btnUp', and '_btnDn' will be assigned references to these elements.

    this.applyTemplate('wj-control wj-inputnumber', templateString, {
  _tbx: 'input',
  _btnUp: 'btn-inc',
  _btnDn: 'btn-dec'
}, 'input');

    @param classNames Names of classes to add to the control's host element. @param template An HTML string that defines the control template. @param parts A dictionary of part variables and their names. @param namePart Name of the part to be named after the host element. This determines how the control submits data when used in forms.

    Parameters

    • classNames: string
    • template: string
    • parts: Object
    • Optional namePart: string

    Returns HTMLElement

beginUpdate

  • beginUpdate(): void

containsFocus

  • containsFocus(): boolean

  • Checks whether this control contains the focused element.

    Returns boolean

deferUpdate

  • deferUpdate(fn: Function): void

  • Executes a function within a beginUpdate/endUpdate block.

    The control will not be updated until the function has been executed. This method ensures endUpdate is called even if the function throws an exception.

    Parameters

    • fn: Function

      Function to be executed.

    Returns void

dispose

  • dispose(): void

  • Disposes of the control by removing its association with the host element.

    The dispose method automatically removes any event listeners added with the addEventListener method.

    Calling the dispose method is important in applications that create and remove controls dynamically. Failing to dispose of the controls may cause memory leaks.

    Returns void

endUpdate

  • endUpdate(shouldInvalidate?: boolean): void

  • Resumes notifications suspended by calls to beginUpdate.

    Parameters

    • Optional shouldInvalidate: boolean

      should invalidate the control. Default value for this parameter is true.

    Returns void

focus

  • focus(): void

  • Sets the focus to this control.

    Returns void

getTemplate

  • getTemplate(): string

  • Gets the HTML template used to create instances of the control.

    This method traverses up the class hierarchy to find the nearest ancestor that specifies a control template. For example, if you specify a prototype for the ComboBox control, which does not specify a template, it will override the template defined by the DropDown base class (the nearest ancestor that does specify a template).

    Returns string

hasOwnProperty

  • hasOwnProperty(v: PropertyKey): boolean

  • Determines whether an object has a property with the specified name.

    Parameters

    • v: PropertyKey

      A property name.

    Returns boolean

hitTest

  • hitTest(pt: any, y?: number): number

  • Gets a number that corresponds to the value of the gauge at a given point.

    For example:

    // hit test a point when the user clicks on the gauge
gauge.hostElement.addEventListener('click', e => {
    var ht = gauge.hitTest(e.pageX, e.pageY);
    if (ht != null) {
        console.log('you clicked the gauge at value ' + ht.toString());
    }
});

    Parameters

    • pt: any

      The point to investigate, in window coordinates, or a MouseEvent object, or the x coordinate of the point.

    • Optional y: number

      The Y coordinate of the point (if the first parameter is a number).

    Returns number

    Value of the gauge at the point, or null if the point is not on the gauge's face.

initialize

  • initialize(options: any): void

  • Initializes the control by copying the properties from a given object.

    This method allows you to initialize controls using plain data objects instead of setting the value of each property in code.

    For example:

    grid.initialize({
  itemsSource: myList,
  autoGenerateColumns: false,
  columns: [
    { binding: 'id', header: 'Code', width: 130 },
    { binding: 'name', header: 'Name', width: 60 }
  ]
});

// is equivalent to
grid.itemsSource = myList;
grid.autoGenerateColumns = false;
// etc.

    The initialization data is type-checked as it is applied. If the initialization object contains unknown property names or invalid data types, this method will throw.

    Parameters

    • options: any

      Object that contains the initialization data.

    Returns void

invalidate

  • invalidate(fullUpdate?: boolean): void

  • Invalidates the control causing an asynchronous refresh.

    Parameters

    • Optional fullUpdate: boolean

      Whether to update the control layout as well as the content.

    Returns void

isPrototypeOf

  • isPrototypeOf(v: Object): boolean

  • Determines whether an object exists in another object's prototype chain.

    Parameters

    • v: Object

      Another object whose prototype chain is to be checked.

    Returns boolean

onGotFocus

onInvalidInput

onLostFocus

onRefreshed

onRefreshing

onValueChanged

propertyIsEnumerable

  • propertyIsEnumerable(v: PropertyKey): boolean

  • Determines whether a specified property is enumerable.

    Parameters

    • v: PropertyKey

      A property name.

    Returns boolean

refresh

  • refresh(fullUpdate?: boolean): void

  • Refreshes the control.

    Parameters

    • Optional fullUpdate: boolean

      Indicates whether to update the control layout as well as the content.

    Returns void

removeEventListener

  • removeEventListener(target?: EventTarget, type?: string, fn?: any, capture?: boolean): number

  • Removes one or more event listeners attached to elements owned by this Control.

    Parameters

    • Optional target: EventTarget

      Target element for the event. If null, removes listeners attached to all targets.

    • Optional type: string

      String that specifies the event. If null, removes listeners attached to all events.

    • Optional fn: any

      Handler to remove. If null, removes all handlers.

    • Optional capture: boolean

      Whether the listener is capturing. If null, removes capturing and non-capturing listeners.

    Returns number

    The number of listeners removed.

toLocaleString

  • toLocaleString(): string

  • Returns a date converted to a string using the current locale.

    Returns string

toString

  • toString(): string

  • Returns a string representation of an object.

    Returns string

valueOf

  • valueOf(): Object

  • Returns the primitive value of the specified object.

    Returns Object

Static disposeAll

  • disposeAll(e?: HTMLElement): void

  • Disposes of all Wijmo controls contained in an HTML element.

    Parameters

    • Optional e: HTMLElement

      Container element.

    Returns void

Static getControl

  • getControl(element: any): Control

  • Gets the control that is hosted in a given DOM element.

    Parameters

    • element: any

      The DOM element that hosts the control, or a CSS selector for the host element (e.g. '#theCtrl').

    Returns Control

Static invalidateAll

  • invalidateAll(e?: HTMLElement): void

  • Invalidates all Wijmo controls contained in an HTML element.

    Use this method when your application has dynamic panels that change the control's visibility or dimensions. For example, splitters, accordions, and tab controls usually change the visibility of its content elements. In this case, failing to notify the controls contained in the element may cause them to stop working properly.

    If this happens, you must handle the appropriate event in the dynamic container and call the Control.invalidateAll method so the contained Wijmo controls will update their layout information properly.

    Parameters

    • Optional e: HTMLElement

      Container element. If set to null, all Wijmo controls on the page will be invalidated.

    Returns void

Static refreshAll

  • refreshAll(e?: HTMLElement): void

  • Refreshes all Wijmo controls contained in an HTML element.

    This method is similar to invalidateAll, except the controls are updated immediately rather than after an interval.

    Parameters

    • Optional e: HTMLElement

      Container element. If set to null, all Wijmo controls on the page will be invalidated.

    Returns void

Events

gotFocus

gotFocus: Event<Control, EventArgs>

Occurs when the control gets the focus.

invalidInput

invalidInput: Event<Control, CancelEventArgs>

Occurs when invalid input is detected.

Invalid input may occur when the user types or pastes a value that cannot be converted to the proper type, or a value that is outside the valid range.

If the event handler cancels the event, the control will retain the invalid content and the focus, so users can correct the error.

If the event is not canceled, the control will ignore the invalid input and will retain the original content.

lostFocus

lostFocus: Event<Control, EventArgs>

Occurs when the control loses the focus.

refreshed

refreshed: Event<Control, EventArgs>

Occurs after the control has refreshed its contents.

refreshing

refreshing: Event<Control, EventArgs>

Occurs when the control is about to refresh its contents.

valueChanged

valueChanged: Event<Gauge, EventArgs>

Occurs when the value of the value property changes.